Salivary nickel and chromium in patients with fixed orthodontic appliances

The purpose of this study was to determine the alterations in the chromium and nickel concentrations in the saliva of orthodontic patients treated wit h fixed orthodontic appliances. Forty-five orthodontic patients were includ ed in this study. The first group consisted of 15 patients (7 female, 8 mal e) with fixed appliances placed in their upper and lower arches. The second group consisted of 15 patients (8 female, 7 male) with a fixed appliance p laced only in the upper arch. The control group consisted of 15 patients (7 female, 8 male) who were not undergoing orthodontic treatment. Four sample s of stimulated saliva were collected from each patient before insertion of the fixed appliance, 1 week after insertion of the appliance, 1 month afte r insertion of the appliance, and 2 months after insertion of the appliance . The same 4 samples of saliva were collected from each control patient at the same time intervals as for the fixed-appliance groups. The chemical ana lyses were done with an electrothermal atomic absorption spectrophotometer (Perkin Elmer 2380, Perkin Elmer Corp, Baden Seewerk, Germany). The Wilcoxo n matched-pairs signed ranks test was used to test differences between samp les before and after insertion of orthodontic appliances. A Kruskal Wallis 1-way analysis of variance was used to test differences in nickel and chrom ium concentration among the 3 test groups. It was observed that there was a large variation in the concentrations of both nickel and chromium in saliv a. No significant differences were found between the no-appliance group and the samples obtained after insertion of the appliances. The results of the study suggest that fixed orthodontic appliances do not significantly affec t nickel and chromium concentrations of saliva during the first 2 months of treatment. (Angle Orthod 2000;70:000-000.).